Fig. 4.

¹³C NMR spectra of PfTx from Pfiesteria. (a) PfTx from P. shumwayae (CAAE1024C) after size exclusion (HW40F column) and subsequent passage through three sequential C₁₈ columns using d4 methanol (*) as a solvent (supporting information. This material, from a fish-fed culture, shows multiple molecular species (congeners) compared with b; arrows indicate peaks in common with b. (b) PfTx from algae-fed P. piscicida (CCMP1832) after the same chromatographic steps used to generate a, followed by passage through a bidentate column using 100% HPLC-grade water as a solvent (supporting information).